Many athletes and others use back-mounted or waist-mounted personal hydration systems to carry water or other drinking liquid with them during strenuous activities. The systems typically include a flexible bag or hydration bladder in which the liquid of choice is contained, and a flexible supply hose running from the bladder to the mouth of a user to allow the user to take in liquids easily. The hydration bladder may be formed with various size fill openings that allow the user to pour water or a desired drink into and out of the bladder, and a removable cap is provided for opening and closing the fill opening. The outermost end of the supply hose is equipped with a valve that prevents air from entering into the system, and selectively enables the dispensing of liquid into the mouth of the user usually upon biting the valve. Such systems are convenient and provide hands-free hydration in lieu of carrying canteens, bottles, cans and other containers.
Once a user has completed activity, the nature of the materials involved in the personal hydration system does not readily allow for drying of the hydration bladder and the supply hose. This allows for retention of the liquid in the bladder for long periods of time, and therefore the possibility for growth of potentially harmful microorganisms, such as bacteria, mold and mildew.